Left ventricular assist device (LVAD) support allows the neonate with congenital heart disease or cardiomyopathy to grow to a larger body weight that is more feasible for complex surgical correction or heart transplant. A paracorporeal LVAD, the Berlin heart ExCor, is FDA-approved for pediatric application. Although this device is outside the body, the outflow graft may still create coronary artery/heart compression. Our ultimate goal is to develop a less invasive and dependable LVAD system for the neonate. The enabling technology will be a small (16-18 Fr) double lumen cannula (DLC), which is inserted from the apex though the LV and aortic valve into the aorta with the drainage lumen opening in the LV and the infusion lumen in the aorta. Coupled with a blood pump, blood is withdrawn from the LV and infused into the aorta to unload the LV though a single cannulation. This DLC-based LVAD: 1) has only one apex cannulation, avoiding heart/coronary artery compression, 2) has a much smaller apex cannulation, eliminating cardiopulmonary bypass, 3) requires a less traumatic left thoracotomy, replacing traumatic medium sternotomy, and 4) has a flexible configuration, allowing a bigger paracorporeal pump for stronger performance and the addition of a gas exchanger for cyanotic heart diseases. Our DLC-based LVAD is much simpler, less invasive, more powerful, and very suitable for neonate application. Our objective in this Phase I SBIR is to develop and fabricate a working prototype of a DLC assembly for a neonate LVAD and to test the prototype's performance in neonate sheep. Our hypothesis is that this new DLC, coupled with a commercial blood pump, will provide total LV support and save the life of sick neonate. It will bridge the patient to recovery, transplant, or further advanced heart surgery. Specific Aim 1: To develop a new TransApical to Aorta (TAA) DLC assembly. A. To design and fabricate a new working prototype of a TAA DLC for a neonate LVAD. The DLC main body outer wall will be constructed with wire reinforced polyurethane. The inner infusion lumen will use an eccentric membrane sleeve. The DLC membrane sleeve infusion lumen extends out of DLC main body to the extension infusion cannula (EIC). The EIC will be reinforced by stainless steel wires across the aortic valve into the ascending aorta. A sewing plate will be designed for sewing the DLC onto the apex, preventing TAA DLC dislodgement. B. Bench testing of the TAA DLC assembly. Bench testing will be done in an ex vivo circuit to measure DLC flow performance. Specific Aim 2: To test our prototype TAA DLC for ease of deployment and 6 hr. in vivo performance. The TAA DLC prototype will be coupled with a CentriMag pump to form a TAA LVAD system. The in vivo new born lamb experiments (n=5) will test the DLC for TAA deployment and in vivo performance. The 16 Fr DLC- based TAA LVAD will pump the blood at a flow rate up to 1 L/min against 200 mmHg ?P. Animal testing results will be used to optimize the TAA DLC design for best performance/reliability for the Phase II grant. Upon this SBIR grant completion, the commercialized TAA DLC will provide a less invasive neonate LVAD.